Figure 4.

Substrate specificity of rA22. rA22 was incubated for 25 min at 37°C with 0.20 pmol of single-stranded, duplex, Y-junction, three-stranded junction, or four-stranded HJ that was 5′-³²P-end-labeled on one strand. Reactions were stopped by addition of SDS and EDTA, and the products were analyzed by electrophoresis on a nondenaturing 10% polyacrylamide gel and visualized by autoradiography. Lanes: 1–5, no recombinant protein; 6–10, 3.2 μg of rA22. DNA substrates are shown diagrammatically above the autoradiograph with the ³²P-end-labeled strand indicated in boldface.